//util.js  
function imageUtil(e) {  
  var imageSize = {};  
  var originalWidth = e.detail.width;//图片原始宽  
  var originalHeight = e.detail.height;//图片原始高  
  var originalScale = originalHeight/originalWidth;//图片高宽比  
  console.log('originalWidth: ' + originalWidth)  
  console.log('originalHeight: ' + originalHeight)  
  //获取屏幕宽高  
  wx.getSystemInfo({  
    success: function (res) {  
      var windowWidth = res.windowWidth;  
      var windowHeight = res.windowHeight;  
      var windowscale = windowHeight/windowWidth;//屏幕高宽比  
      console.log('windowWidth: ' + windowWidth)  
      console.log('windowHeight: ' + windowHeight)  
      if(originalScale < windowscale){//图片高宽比小于屏幕高宽比  
        //图片缩放后的宽为屏幕宽  
         imageSize.imageWidth = windowWidth;  
         imageSize.imageHeight = (windowWidth * originalHeight) / originalWidth;  
      }else{//图片高宽比大于屏幕高宽比  
        //图片缩放后的高为屏幕高  
         imageSize.imageHeight = windowHeight;  
         imageSize.imageWidth = (windowHeight * originalWidth) / originalHeight;  
      }  
       
    }  
  })  
  console.log('缩放后的宽: ' + imageSize.imageWidth)  
  console.log('缩放后的高: ' + imageSize.imageHeight)  
  return imageSize;  
}  
  
module.exports = {  
  imageUtil: imageUtil  
}  